Introduction

Lateral epicondylitis, or “tennis elbow,” is a frequently diagnosed condition and a common cause of pain around elbow joint. The complaint is characterized by pain over the lateral epicondyle of the humerus, which is aggravated with resisted dorsiflexion of the wrist. The incidence is approximately 4 to 7 per 1000 patients per year [1].

Lesion can be in common extensor tendon, extensor Carpi radialis brevis (ECRB), or radial collateral ligament but most commonly extensor Carpi radialis brevis (ECRB) is involved [1].

Repeated tendon overuse leads to micro tear in tendon when stretch exceeds physiological limit of the tissue. There is ongoing inflammatory process besides change in complex tendon structure. Generation of pain may be due to irritation of mechanoreceptors by traction or shear forces or activation of nociceptive receptors by neurotransmitters such as substance P [2].

Several modalities of treatment have been developed which includes rest, nonsteroidal anti-inflammatory drugs, physical therapy, tennis elbow belt, corticosteroid injection, botulinum toxin injection, Extracorporeal shock wave and pulsed ultrasound. One of these treatments is injection of platelet-rich plasma (PRP) which is an autologous blood product enriched with biological factors responsible for tissue regeneration.

Corticosteroid work as short-term measure by reducing the inflammation but it doesn’t deal with the root cause of inflammation as PRP does.

The use of platelets as vehicles for the delivery of growth factors in the form of platelet rich plasma (PRP) may be just the beginning of a new medical frontier known as ‘‘orthobiologics.’’ Since 1992 Platelet-rich plasma (PRP) is a new technology focused on enhancing the healing response after injury of different tissue types [3].

Platelet rich plasma is defined as the plasma fraction of autologous blood having a platelet concentration above baseline. Study has shown clinical efficacy of PRP use with minimum concentration of platelets by four times as compare to autologous blood [4].

As PRP is an autologous blood product, it is free of transmissible diseases and cannot cause hypersensitivity reactions.

Results

This technique involved a single skin portal and then 5 penetrations of the tendon. Patients in steroid group received 2 ml of methylprednisolone (40 mg/ml, inj).

Immediately after the injection, the patients were kept in a supine position without moving the arm for 15 minutes. Patients were sent home with instructions to limit their use of the arm for approximately 24 hours and use acetaminophen for pain.

A formal stretching and strengthening exercises of forearm muscles were initiated on 2nd day after injection. At 4 weeks after the procedure, patients are allowed to proceed with normal sporting or recreational activities as tolerated.

The patients were assessed using Visual analogue scale (VAS), Disability assessment of Shoulder and Hand score (DASH) score before and after treatment at 2, 8 weeks and 3, 6 months. Total 60 patients were included in study (30 in each group), demographically both groups were similar (Table 1).

Mean VAS Score (Figure 1) and DASH score (Figure 2) before treatment and at each follow-up were compared (total 5 mean and 2 groups).

Table 1: Demographic Data of Both Groups

Figure 1: Mean VAS score (PRP vs. Corticosteroid group)

After 6 months of follow up the effect in PRP group was maintained and declined in Corticosteroid group. This concludes that PRP is more helpful in treating lateral epicondylitis.

Corticosteroid injection which was gold standard treatment for lateral epicondylitis, is considered controversial now a days because studies have proved that it offers only short-term relief as compare to physiotherapy and wait and watch policy [13, 14].

Often results are poor after 3 months of follow-up, there is higher occurrence of relapse probably because steroid leads to permanent changes within microstructure of tendon as patient has tendency to overuse the arm after injection as a result of direct pain relief [15].

Platelet rich plasma is an ideal biologic product in which patients own platelets are collected into a highly concentrated form. Platelets release more than 95% of the pre-synthesized growth factors within one hour of activation. This initial burst is followed by steady synthesis and secretion of growth factors for their remaining life span [16].

No activation agent was used during our procedure, as platelets get activated in vivo when exposed to thrombin which in turn produced in response to injection of platelets using a peppering technique and exposed collagen also acts as a natural activator of platelets [17].

There is concern regarding use of bovine thrombin as activator, being an exogenous substance, it can produce detrimental effects and collagen is naturally involved in clotting cascade and is attractive alternative to bovine thrombin.

Use of leukocyte rich or leukocyte depleted PRP is a topic of debate, presence of leukocyte in PRP augments its antibacterial activity and have ability to debride the tendon and start healing (as leukocytes also contains growth factors).

Presence of matrix metalloproteinase (released from neutrophils) have detrimental effects on tissue healing but this fact needs to be proved by Randomized control trials. Injection of autologous Platelets has been shown to improve repair in tendinosis in animal studies [17,18,19].

Effect of single injection PRP last for 1 year whereas percentage of success rate for corticosteroid injection drops from 51 % to 40 % after 2 years of follow-up [17].